The subject matter of the present invention relates generally to tapered wooden structural members or beams, and in particular, to tapered wood I-beams and their method of manufacture. Such wood I-beams are especially useful in making trusses or joists for the floor or ceiling of a building or for other structures.
Previously wood I-beams have been made of a uniform width by automatic manufacturing machines of the type disclosed in U.S. Pat. No. 3,894,908 of Troutner et al, issued July 15, 1975 and U.S. Pat. No. 3,616,091 of Troutner, issued Oct. 26, 1971. In addition, it has been previously proposed to form a wood roof truss with tapered I-beam sections as shown in U.S. Pat. No. 3,991,535 of Keller et al, issued Nov. 16, 1976 and U.S. Pat. No. 3,490,188 of Troutner, issued Jan. 20, 1970. However, such roof trusses have had spaces between adjacent I-beam sections and the tapered I-beam sections have been made manually for the most part, not produced by automatic manufacturing machines.
The method of manufacture of the present invention enables tapered wood beams, such as I-beams, to be produced substantially entirely by automatic manufacturing machines, thereby greatly reducing their cost of manufacture. The present method includes first producing an I-beam of uniform width, next cutting the I-beam into two portions by sawing the web member of such beam along a diagonal line to form two tapered width web members, and then fastening additional flange members to the sawn edges of such tapered web members. In addition, by using the method of manufacture of the present invention the same automatic manufacturing machines which produce wood I-beams of uniform width can also be employed to manufacture wood I-beams of tapered width. This is accomplished by releasably clamping or otherwise fastening the cut portions of the uniform width I-beam together in back to back relationship at the first flange members of such portions to form an assembly of tapered web members and flange members which is of uniform width so it can be transmitted through such machine. The machine glues second flange members to the cut edges of the tapered web members to produce two tapered I-beams which are then unclamped to separate such beams. As a result, the manufacturing costs of the tapered I-beams made by the method of manufacture of the present invention are further reduced.
It has been previously proposed to cut steel I-beams in two along a diagonal to provide two tapered T-shaped beam sections which are then reassembled to produce a tapered steel pole assembly as shown in U.S. Pat. No. 1,594,658 of Bushong, issued Aug. 3, 1926 or a structural metal member such as a purlin as shown in U.S. Pat. No. 899,033 of Dodds, issued Sept. 22, 1908. However, in neither of these patents are the tapered I-beam portions fastened together in back to back relationship at their flanges to position the cut edges of the web member outwardly and to attach a second pair of flanges to such cut edges of the web member in order to form two tapered I-beams in the manner of the present invention.